Trigonometrymedium · Past Paper
If sin θ + sin²θ = 1, then the value of (cos²θ + cos⁴θ) is:
A0
B1
C2
D1/2
✓ Correct Answer: B — 1
sin θ = 1 - sin²θ = cos²θ. Therefore cos²θ + cos⁴θ = sin θ + sin²θ = 1.
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